WASHINGTON (AP) _ President Bush on Wednesday acknowledged previously secret CIA prisons around the world and said 14 high-value terrorism suspects _ including the mastermind of the Sept. 11 attacks _ have been transferred from the system to Guantanamo Bay for trials.

He said a small number of detainees have been kept in CIA custody including people responsible for the bombing of the USS Cole in 2000 in Yemen and the 1998 attacks on U.S. embassies in Kenya and Tanzania, in addition to the 2001 attacks.

``It has been necessary to move these individuals to an environment where they can be held secretly, questioned by experts and, when appropriate, prosecuted for terrorist acts,'' Bush said in a White House speech. Families of some people killed in the Sept. 11, 2001, attacks made up part of the audience.

Bush said of the suspects: ``These are dangerous men, with unparalleled knowledge about terrorist networks and their plans of new attacks. The security of our nation and the lives of our citizens depend on our ability to learn what these terrorists know.''

The announcement from Bush was the first time the administration had acknowledged the existence of CIA prisons, which have been a source of friction between Washington and some allies in Europe. The administration has come under criticism for its treatment of terrorism detainees. European Union lawmakers said the CIA was conducting clandestine flights in Europe to take terror suspects to countries where they could face torture.

``Today the administration finally recognized that the protections of the Geneva Convention should be applied to prisoners in order to restore our moral authority and best protect American troops,'' said Sen. John Kerry, D-Mass. ``Today's shift in policy follows the sad legacy of five years during which this administration abused our Constitution, violated our laws and most importantly failed to make America safe.''

Bush has sought with a series of speeches to sharpen the focus on national security two months before high-stakes congressional elections.

The president successfully emphasized the war on terror in his re-election campaign in 2004 and is trying to make it a winning issue for Republicans again this year.

Bush said the CIA program has involved such suspected terrorists as Khalid Sheik Mohammed, believed to be the No. 3 al-Qaida leader before he was captured in Pakistan in 2003; Ramzi Binalshibh, an alleged would-be Sept. 11 hijacker; Abu Zubaydah, who was believed to be a link between Osama bin Laden and many al-Qaida cells before he was captured in Pakistan in 2002.

The list also includes Riduan Isamuddin, known as Hambali, who was suspected of being the mastermind of a string of deadly bomb attacks in Indonesia until his 2003 arrest in Thailand.

Defending the prison program, the president said the questioning of these detainees has provided critical intelligence information about terrorist activities that has enabled officials to prevent attacks, including with airplanes, within the United States. Other attacks thwarted through intelligence gathered in the program include a planned strike with an explosives-laden water tanker on U.S. Marines at Camp Lemonier in Djibouti, an attack with car and motorcycle bombs on the U.S. consulate in Karachi, and a plot to fly passenger planes into London's Heathrow Airport or Canary Wharf, Bush said.

Bush would not detail interrogation techniques used through the program, saying only that they are tough but do not constitute torture. He did use language that suggested its nature, saying the CIA turned to an ``alternative set of procedures'' that were successful after Zubaydah and others had stopped providing information.

``This program has helped us to take potential mass murderers off the streets before they have a chance to kill,'' the president said.

A senior administration official said that fewer than 100 people have been detained under the CIA program, rejecting allegations that perhaps thousands have been held in secret prisons. With the transfer of the 14 detainees to Guantanamo, the CIA is no longer holding any suspects, the administration official said. He added, however, that the administration wants the program to continue.

The president said the 14 key terrorist leaders, including Mohammed, Binalshibh, and Zubaydah, who have been transferred to the U.S. military-run prison at Guantanamo Bay would be afforded some legal protections consistent with the Geneva Conventions.

``They will continue to be treated with the humanity that they denied others,'' Bush said.

Bush also laid out his proposal for how trials of such key suspected terrorists _ those transferred to Guantanamo and already there _ should be conducted, which must be approved by Congress. Bush's original plan for the type of military trials used in the aftermath of World War II was struck down in June by the Supreme Court, which said the tribunals would violate U.S. and international law.

``As soon as Congress acts to authorize the military commissions I have proposed, the men our intelligence officials believe orchestrated the deaths of nearly 3,000 Americans on Sept. 11, 2001, can face justice,'' the president said.

Aides said the legislation being introduced on Bush's behalf later Wednesday on Capitol Hill insists on provisions covering military tribunals that would permit evidence to be withheld from a defendant if necessary to protect classified information.

As part of the package, Bush asked Congress to shield from prosecution or lawsuits federal personnel who handle terrorist suspects.

``Passing this legislation ought to be the top priority,'' Bush said.

Republican Sens. John McCain and Lindsey Graham have drafted a rival proposal. It would guarantee certain legal rights to defendants, including access to all evidence used against them.

``I think it's important that we stand by 200 years of legal precedents concerning classified information because the defendant should have a right to know what evidence is being used,'' said McCain, R-Ariz.

Administration officials also have said that allowing coerced testimony in some cases may be necessary, while McCain said the committee bill would ban it entirely. ``We have some differences that we are in discussion about,'' said McCain, who had not seen the White House bill in writing.

Senate Majority Leader Bill Frist, R-Tenn., is expected to side with the administration. He planned to introduce Wednesday the White House legislative proposal on the floor and refer it to the Armed Services Committee for review.

Also on Wednesday, the Pentagon put out a new Army field manual that spells out appropriate conduct on issues including prisoner interrogation. The manual applies to all the armed services, but not the CIA.

It bans torture and degrading treatment of prisoners, for the first time specifically mentioning forced nakedness, hooding and other procedures that have become infamous during the war on terror.

The United States began using the Guantanamo Bay Naval Base in eastern Cuba in January 2002 to hold people suspected of links to al-Qaida or the Taliban. About 445 detainees remain there, including 115 considered eligible for transfer or release.

The president said he eventually wants to close Guantanamo as critics and allies around the world have urged. But he said that cannot happen until Congress creates the process for trying its most dangerous prisoners, and other countries negotiate acceptable terms for taking back their citizens who are being held there.